Automatic door operator



Sept. 28, 1948. c. sc ME r AL 2,450,021

AUTOMATIC DOOR OPERATOR 3 Sheets-Sheet 1 Filed Aug. 27, 1945 IN VEN T ORJ Sept. 1948- c. T. SCHIRMER ETAL 2,450,021

AUTOMATIC DOOR OPERATOR 3 Sheets-Sheet 2 Filed Aug. 2'1, 1945 WWW NYE 012s Se t. 28, 1948. c. T. SCHIRMER E TAL 2,450,021

AUTOMATIC DOOR OPERATOR 3 Sheets-Sheet 3 Filed Aug. 27, 1945 Patented Sept. 28, 1948 AUTOMATIC DOOR OPERATOR Cyrus '1. Schirmer, Wayland. and Max Knobel,

Arlington,- Mass., assignors, by mesne assignments, to Redmond Company, Inc., a corporation of Michigan Application August 27, 1945. Serial No. 612,924

6 Claims. (Cl. 318-452) The present invention relates to automatic door operators, more particularly to apparatus under control of the driver for opening and closing garage doors without requiring him to leave the vehicle.

Various devices have been suggested for automatic operation of garage doors but, so far as. we are aware, most of them have proved impractical either because of complexity or uncertainty of operation.

The principal object of the present inventio is to provide a door operator particularly useful for automatic garage door operation which requires no special attachments to the vehicle and which is capable of certain operation for either opening or closing the door. To this end the principal feature of the invention comprises a photoelectric control which may be operated by blinking the headlights several times within a definite period. Another feature comprises means whereby the device is rendered sensitive only to light directed on the photoelectric control from a predetermined direction or within a small angle therefrom in order that the device will be substantially insensitive to extraneous light sources and will respond to the blinking operations.

Another object is to provide a device so arranged that the automatic apparatus can be rendered inoperative by means of a key switch.

In the accompanying drawings, Fig. 1 is a diagram showing the relation of an automobile to the garage when the door is to be opened or closed; Fig. 2 is a detail illustrating a part of the door operatingmechanism: Fig. 3 is an elevation, partly in section, of the control apparatus; Fig. 4 is a plan view of the apparatus shown in Fig. 8; Figs. 5 and 6 are diagrams of the electrical connections; and Fig. 7 is a diagram illustrating the means for obtaining directional sensitivity.

As shown in the diagram of Fig. 1 a garage indicated diagrammatically at 'l is provided with a (were of the overhead type. The door constructipg'and the motor connectons for operating it aredescribed in detail in co-pending application of Schirmer, Serial No. 612,921, filed August 27, 1945. It is sufiicient to note here as shown in Fig. 2 that when the door is closed a vertical link Ill prevents the door from being lifted manually. The link It is connected to a carriage it, operated by a chain It which is driven by a motor ll (Fig. 5). To open the door the carriage is drawn to the left. thus pulling the link it toward a horizontal position and drawing the door into overhead position. To close the doorthe carriage is moved in the opposite direction.

Referring again to Fig. 1, this shows an automobile it stopped in front of the garage with one of the headlights directed toward a control device It on the door frame. Fig. 3 is a sectional view of the control device It. It comprises two telescoping tubes 20 and 22. The bottom tube 22 carries a protruding lens 24 to focus light from the headlights on to the sensitive element of a phototube 26. Between the lens and the tube there is mounted a diaphragm :8 having an aperture 30 arranged to insure that light coming only from a certain direction will reach the tube, as will be explained in detail later with reference to Fig. '7. Mounted within the telescoping tube 22 are also a cold-cathode amplifier II, a transformer 34, and a relay 35, connected as shown in the wiring diagram of'Fig. 5 to be presently explained. The telescoping tube 22 is adjustable-- for height and orientation within the tube 20, so that the light from the car may be directed on the lens 24 when the car is stopped at a certain position in the driveway. The upper tube is secured to thedoor frame by brackets 36. The tubes 2. and 22 may be secured together in adjusted position by means of a clamp 38.

In the top of the upper tube -20 is mounted a pilot light 40 which is arranged to give a suitable indication when the phototube is activated. The invention also includes a manual push button operating switch 42 and a lock switch 44 which may be conveniently mounted in the same assembly with the pilot light. The remaining parts of the equipment will be described in connection. with the wiring diagram of Fig. 5.

In Fig. 5, the alternating current supply lines are shown at 43, and are designated and for convenience, although those symbols have no signiflcance as to polarity. The line is connected to one side of the primary of the transformer 34 through the normally closed lock switch 44, and the line is directly connected to the other side. One 'side of the transformer secondary is connected to the cathode of the phototube "in the conventional manner, a center tap on the transformer is connected to the cathode of the email-- her 32, and the other side of the secondary is connected through a series condenser 45 and resistor 48 with the anode of the phototube, the junction of 45, 46 being connected to the amplifier grid.

'the' line.

contact 41 is connected by a wire with the line below the lock switch. and the contact ll is connected by wires II and II with the step coil 34 o! a ratchet relay indicated generally at It, the coil being connected by a wire ll with the line. The push-button switch 42 has its contacts connected across the relay contacts sothat the operations which are performed by the main relay may alternatively be performed manually.

The ratchet relay It has an armature 58 connected with a pawl N to drive a ratchet wheel 02. A detent pawl N is also provided in accordance with usual ratchet construction. The relay is provided with a set oi main contacts 86, 81 by which the operation of the motor is controlled. Furthermore, as will hereinafter appear, the system preferably is provided with time controlled reset means for which purpose the relay has a pair oi contacts it, 6!. Auxiliary contacts ll, H may also be provided for controlling garage lights -as 'will later be described.

The ratchet wheel 82 is provided with a cam suriace II which closes contacts 68, 61 together on the third step to determine operation oi the motor. The auxiliary contacts II, II are arranged to be closed by the cam 11 on the fourth step.

Contacts it and 88 are together connected to the line by wire 14. Contact 61 is connected by --wire (I with the winding 11 of a motor relay which is connected to the line through a wire II. The armature II is connected to the wire 14 which as heretofore described, connects with the line. A contact It on which the armature It closes is connected with the motor I! in a manner to be described later. upon closure of the contacts It, I! on the third step the motor relay is energized by a circuit running from the line through connection ll, winding I1, contacts ll, 8! and connection it to the line.

As stated above, a time controlled reset device ispreferably included in the system, in order to reset the ratchet in the event that three stepping operations of the relay are not completed within a specified time. To this end, contact 8! is connected by a wire Ii through the primary of a transformer 82 which in turn is connected with The secondary oi the transformer I2 is connected to a bimetallic thermal reset device I, which if energized for a sufllcient period of time, flexes into engagement with a pivoted armature 88, forming a part of a reset relay 88. The armature has an arm I to lift and release the pawls" and 64 after the thermal device has been energized for a predetermined time.

A spring Si is provided to restore the ratchet to the position shown in Fig. 6, whenever the pawls are tripped.

The motor relay contact III is connected by a wire Ill with the motor Ii. The motor is herein shown as a split-phase condenser motor having windings I" and I" both connected to the wire III.

A condenser H0 is connected between the two windings.

A door limit reverse switch is provided to de- -termine opening and closing movements of the It will be seen that,

tion to the other at the end of an opening or closing movement.

The limit switch cam is provided with a projection I". arranged to close contacts I" momentarily in the shift from one position to the other. The contacts are connected between wire I" and the reset relay 80, which is connectedto the line by a connection I. Thus momentary closure of the contacts I32 during movement of the limit switch in either direction energizes the relay and lifts the pawls I and II.

The auxiliary contacts II and H of the ratchet relay are for the purpose of lighting a garage lamp and will later bedescribed in detail.

The pilot lamp 4| is connected between the line and the connection I! whereby it will light whenever the contacts of the main control relay 3! or the manual switch 42 are closed.

The operation of the door-operating parts is explained as follows: Assuming that the doors are closed and the car drives up for access, the driver will stop the car at a designated position in the driveway. The exact position of stopping is not critical and any position within the limits of about flve feet will serve to operate the system. The control device II will have been adjusted so that when the car is within the correct stopping range the light lrom at least one headlight will be directed toward the phototube. At this time the limit switch is in the position shown in Fig. 5. The driver after stopping at the proper position turns his headlights on and oil three times. The system operates equally well in daylight and at night, but at night the impingement of the already lighted headlights on the phototube. causes the first actuation of the relay.

Each time the headlight is lighted the phototube is activated and through the amplifier It causes energization of the main relay II and closure of its contacts 41, ll. Upon closure of the relay contacts a circuit is traced from the line below the key switch through the connection II, the relay contacts 41, 4t, and the connections II and nected through I1 to the line. Thus the step magnet is energized for each blink of the headlights. The pilot lamp ll is also energized in unison with the step magnet, so that the driver is advised of correct operation. Each energisetion of 4 the step magnet advances the ratchet wheel I by one tooth. 0n the first advance the contacts I and II are closed, thereby energizing the thermal time delay reset member I through the transformer 82. The thermal member U4 is adapted to engage the armature It and trip the pawls at the end oi a specified time, say about 20 seconds, so that if the proper door-operating signal is not completed within that time, the ratchet will automatically reset without causing any operation of the motor. The thermal reset thus distinguishes between desired operation and such accidental illumination of the phototube as might occur, for example, from the sun shining on it at a particular time of day or by illumination from a passing vehicle.

On the secondstep of the ratchet none of the electrical connections are changed. 0n the third step, however, contact OI drops oi! the cam and opens the thermal reset circuit, thus preventing the thermal reset from interfering with the opening of the door. Also on the third step, contacts II and 81 are closed, thereby energizing the motor relay to close its armature 1! on contact II. The circuit from the motor is then traced from the line, through connection 14, contacts II and II,

all of the previously described circuits. The operation of the limit switch leaves contact no closed on H4, thus changing the motor connections in readiness for operation of the motor for a closing movement, The operator may then drive into the garage.

To close the door the operator simply presses the manual button d2 three times. Since the contacts of this button are connected directly across the relay contacts d1, 88, the same operations are performed as if the phototube were actuated by the headlights, except that the motor connections are changed by the limit switch. The winding I'M is now the main winding while I is the condenser winding. The motor operates in the reverse direction to close the door and upon reaching the limit of its closing movement, the limit switch is rocked to place the contacts in position for a subsequent opening movement. The push button switch 42 may be located on the top of the control assembly i8 as indicated in Fig. 3'; or ii the garage has another door commonly used for access the switch may preferably be placed at a convenient position in the garage.

When thedoor is to be opened to permit egress of the vehicle this is accomplished by operating the manual button 62 three times. The car is backed out, and then, by blinking the lamps three times, the system is automatically operated to close the door.

The system'may be disabled at any time by the key switch it which simply opens the supply line to the main transformer 34. The door cannot then be opened from the outside by any unauthorized persons since the vertical link connection shown in Fig. 2 prevents its being lifted manually. The system may later be restored for automatic operation by closing the key switch. The key switch is preferably placed at the top of the unit i8 as shown in Fig. 4. The above-mentioned copending Schirmer application describes means for gaining access to the garage when the electrical system is disabled, as by failure of the supply.

The auxiliary contacts i0 and II of the step relay are provided for optional operation of other devices. Preferably these contacts are used to light or exting-igish lamps in the garage or driveway. The auxiliary contacts remain open on the first three steps of the ratchet but on a fourth step, which is optional, they are closed by the cam surface 12. The contacts I0 and Ii are connected with wires I36 and I38 which, as shown in'Fig. 6, are connected respectively to one side of the supply line and to a step relay magnet I", which in turn is connected by a wire I42 with the other side of the line. The step relay includes a ratchet wheel I operated by an armature M6. The ratchet operates a multiple-lobe cam I to control contacts I50 and 152. The shape of the cam is such that successive steps of the ratchet alternately open and close the contacts. The contacts are connected in series with the lamps to be con- 3 trolled, which are indicated diagrammatically at I'll. It will be seen that one step of the ratchet will light the lamps. the next step will extinguish them. and so on.

Manual control of the lamps is provided by push button switches lit which may be located at convenient positions in the house and garage. The

contacts of the push button switches are in parallel to each other and to the relay contacts I! and ii, so that closure of any of the contacts will simply result in advancement of the ratchet l by one step, thus either lighting or extinguishing the lamps W8.

If the operator desires to control operation of the lamp W5 from the car, he will simply blink the headlights tour times. The first three blinks cause operation of the door as heretofore described. The fourth blink advances the ratchet 52 by one step. This does not affect the door control contacts but does close the auxiliary contacts li t, it. Thus. without leaving the car, the driver itiay turn the lamps on before driving into the garage or turn them of! after leaving". the garage. Since the ratchet i is merely advanced one step for each energization of the step magnet in. the lamp contacts are not affected by release of the pawls 80 and 64 of the ratchet relay 5,5. Hence, the lamps will remain either on or on until a subsequent energization oi='the magnet M0. by closure of the auxiliary contacts H. II

the push button contacts we.

With respect to the lock switch 4, it will be noted that after door operation is initiated by the ratchet relay, the lock switch may be opened, even before completion of the door. movement. The door will complete its movement but thereafter the system will be disabled with the lock the lens as, diaphragm 28 and the cathode of tube 28 are shown diagrammatically. The plane of t diaphragm as is spaced from the lens so that e center of the aperture 38 is one of the conjugate points for the center of headlamp of the vehicle when the vehicle is stopped at the proper position in the driveway. Thus. the image of the head lamp is formed in the plane of the diaphragm 28; in other words, the diaphragm is substantialiy in the focal plane. This it; indicated by the conventional geometric construction of Fig. 7 wherein the object (head lamp) isjshown as an arrow, and the image is indicated by an inverted arrow in the plane of the diaphragm 2!. Beyond the aperture the light diifuses on to the cathode of the tube, and preferably the cathode is spaced at such a distance that it is substantially covered by the light coming through the aperture. The device is sensitive only to light included within the cone whose elements pass from the center of the lens to the edge of the aperture, thus for a lens of 3" focal length and an aperture of 0.25", the field of the device is a cone having an angle of about 2.5 between its axis and any element. For any source of light outside the cone, rays which, without the diaphragm. would be refracted by the lens onto the cathode, are

stopped by the diaphragm.

when the aperture is oi such a size as exactly to frame the image of thehead lamp. Thus, tor the specific example given above, an eight-inch lamp spaced 8 feet from the lens with its center on the lens axis would form an image Just filling the aperture. To take care of normal variations in the stopping position of the vehicle, as well as lens aberrations, the aperture is preferably somewhat larger than the minimum; thus an aperture of two or three times minimum diameter may be used, and will have a sumciently restricted iield.

The principal importance of this arrangement is that it makes the system sensitive only to the blinking operation. If the phototube were allowed to have a much wider field, it might be continuously illuminated by an extraneous source (skylight,.street lamps, etc.) at a considerable angle from the predetermined direction and hence might not respond to the changes of illumination caused by the blinking operation. But within the narrow field defined-by the aperture N, the vehicle itself will shield the device from any extraneous illumination. For example, consider an extraneous light source in the field oi the device at a time when the car is not in door-operating position. The phototube is continuously illuminated and the step magnet II is continuously energized. Thera'tchet will have advanced one step. If the timlng'reset is used, the ratchet will have-returned to its original position, but the pawl will-be held attracted by the magnet 54, so that the ratchet will not be thereafter operated. Ii no timing reset is used the ratchet will remain on the first step. In any case, when the vehicle drives intoproper position for door operation, the body of the vehicle will shade the lens from the extraneous source. The system will then respond to the blinking operation. It will be seen that the timing reset means isnot essential to guard against the condition described above, but is preferably-provided to guard against false operation byvariations in extraneous illumination.

The door operating means of the present inroadway contacts, and without the necessity of applying any'speclal equipment to the car. The

system operates without any appreciable power drain, since the primary oi transformer 34 is the only part connected to the lines during inactive periods. Ample security is afiorded by the provision of the lock switch I.

Having thus described the invention. we claim:

1. An automatic garage door operator comprising a phototube adapted to be activated by the headlight of an automobile,- a step relay operable upon each activation of the tube, reset means for restoring the step relay, timing means for operating the reset means a predetermined time after operation or the step relay, motor control contacts operable on a selected number of steps of the relay, in a time less than said predetermined time, and limit and reverse switch means for controlling the motor.

2. An automatic garage door operator comprising a phototube adapted to be activated by the headlight of an automobile, a step relay operable upon each activation of the tube, reset means for restoring the step relay, timing means for operating the reset means a predetermined time alter operation of the step relay. motor control contacts operable on a selected number oi steps oi the relay, in a time less than said predetermined time, and auxiliary contacts to be optionally operated upon an additional step or the relay following closure of the motor control contacts.

3. An automatic garage door operator comprising a phototube adapted to be activated by the headlight oi an automobile, a step relay operable upon each activation oi the tube, reset means for restoring the step relay, timing means for operating the reset means a predetermined time after operation or the step relay, motor control contacts operable on a selected number or steps bi the relay, in a time less than said predetermined time, and auxiliary contacts to be optionally operated upon an additional step of the relay iollowing closure 01 the motor control contacts, a second step relay controlled by said aux- ;iliary contacts, and contacts alternately opened and closed upon successive steps oi said second relay.

4. An automatic garage door operator comprising a motor, a phototube, a step relay operable upon each activation of the phototube, a reset device ior the step relay, thermal timing means controlled by the step relay to operate the reset device a predetermined time after initiation of operation oi the step relay, motor control contacts operable upon a selected number of steps or the relay, within said predetermined time. and an automatic reversing limit switch having provision for determining the direction oi motor operation. r 5. An automatic garage door operator comprising a motor, a phototube, a step relay operable upon each activation oi the phototube, a reset device for the step relay, thermal timing means, contacts controlled by initial steps of the relay to energize the thermal timing means, motor control contacts controlled by a subsequent step of the'relay, the timing means being deenergized upon operation oi the motor control cont'acts, and an automatic reversing limit switch having provision for determining the direction of motor operation. 6. An automatic garage door operator comprising a phototube adapted to be activated by the headlight 01' an automobile, a step relay operable upon each activation 0! the tube, reset means i rrestoring the step relay, "timing means for rating the reset means a predetermined time ter operation oi the step relay, motor control contacts operable on a selected nirmber of steps 0! the relay, an optical system ior'fthe phototube fiicluding a lens, and a field-limiting diaphragm in the neighborhood or the focal plane of the lens, .the phototube being disposed in back of the diaphragm to receive diiiuse light passed therethrough.

CYRUB T. SCHIRMER. MAX KNOBEL.

REFERENCES CITED Theiollowing references are of record in the die of this patent:

UNITED STATES PATENTS 

